福建省林木良种繁育概况及今后工作设想

本文介绍了福建省林木种质资源的收集保存、研究利用，优良家系选育，树种内种源研究，高世代种子园研究，乡土树种栽培驯化，外来树种引种，提高种子园种子产量所采取的措施，无性繁殖技术等林木良种繁育概况；并就林木育种工作存在的问题及今后工作设想提出建设性意见。     

西方经济学基本假设与中国传统思想

本文着力分析西方经济学行为假设与中国传统思想的矛盾之处,探讨依托中国传统思想的中国经济学和经济行为之特色。     

基于非线性假设的农业机械化综合评价——以四川地区为例

农业机械化水平受到自然、经济、社会等多重因素影响,区域性特征非常明显,对农机化的评价维度和方法目前也未形成共识。为此,以四川省农机发展水平为例,确定四川省农业机械化评价维度后,基于几个维度的非线性关系假设,使用三维空间向量对该地区农业机械化水平进行了综合评价。     

Primary Study of Applicability of Plane-section Assumption of Shaped RC Columns

Adopting the element SOLID65 and LINK8 in the general finite element analysis software ANSYS and fiber model beam-column element based on finite element flexibility method respectively, the comparative analysis of the cross, L and T-shaped RC columns under compression, bending, shear and torsion with flange width-thickness ratio of 4:1 is carried out. The applicability of plane section assumption in the nonlinear analysis is discussed primarily, which shows that it is feasible on the whole for shaped RC columns with flange width-thickness ratio equal to or smaller than 4:1.     

近年来生态足迹研究进展

本研究对国内外生态足迹的理论假设、计算方法、贸易赤字、生态超载和基于生态足迹分析的可持续发展静态和动态评估进行了简要介绍,详细讨论了生态足迹的理论假设、计算方法等;回顾了近年来国内外的进展,其研究应用范围从省级行政区进一步扩展到乡镇级行政区和能源、旅游、种养殖业、交通、贸易、大学等产业领域的研究,动态研究也大量增加;对生态足迹理论和应用研究在流动人口、地区生态足迹分析的理论假设、基于生态足迹分析的可持续状况横向比较、各类土地互斥假设、生态足迹分析理论在用于城市型国家或城市等人口高密集地区或不发达地区的可持续性测度时的限制等方面存在问题,提出了相应的改进意见和建议。文章的最后指出了国内围绕生态足迹研究应尽快开展的工作:积极开展生态足迹理论和方法的改进与完善研究、开展上年结转和本年结余资源对生态足迹计算的影响研究、开展国家公顷和省公顷等地方公顷研究,以及积极开展水产养殖渔业、圈养牧业均衡因子研究等。     

林木生长与养分动态模型研究Ⅲ.生长方程的假设与前提

结合实例对吴和胡提出的杉木直径、高和蓄积生长方程的基本假设和边界条件进行了详细的说明和论证,并在直径和高生长方程的基础上给出了杉木径高比系数的动态方程．径高比系数随树龄增长而递减的规律表明杉木直径和高的生长速率递减存在不同步现象,产生这一现象的主要原因是林木生长的平面限制效应大于高度限制效应,因此,森林蓄积增长的主要限制因子是树木的直径生长速率．     

A distributed hydro-environmental watershed model with three-zoned cell profiling

A cell-based distributed watershed model is developed which enables us to simulate the hydrological and hydraulic aspects of the watershed in a refined fashion. With three-zoned cell profiling, the model is composed of three sub-models; tank model for a surface water zone, soil moisture model for a surface soil zone, and unconfined shallow groundwater flow model for a subsurface zone. Inclusion of the soil moisture sub-model modified to reroute the infiltration, routed from the tank sub-model, into the return flow and the groundwater recharge features the model. The groundwater flow sub-model, numerically approximated by use of the finite volume method and the implicit time-marching scheme, considers a network of on-farm drainage canals as internal boundaries, which is an essential need for modeling the watershed including farmlands. Cascade-linking of the three sub-models in a cell and assembling of all the cells over the entire watershed domain provides the global equations system to be solved. Applicability of the model is demonstrated with its practical application to a real watershed in that paddy and upland crop fields take great part of the land-use practice. It is then indicated in a quantified manner that rice farming significantly contribute as a major groundwater recharger in an irrigation period to fostering and conservation of regional water resources. Along with appropriately profiling a cell, the model is so versatile and tough that it can be applied without difficulty to a watershed of diverse terrains and land-uses and the computations can stably be carried out. It is thus concluded that the model presently developed could be a powerful “watershed simulator” to investigate and assess the time-varying hydro-environmental properties of a watershed while separating and integrating the hydrological and hydraulic components of particular importance.     

Analysis of Influencing Factor of Land Price Based on Bootstrap Method

There are a lot of influencing factors of land price. Method of t-test of regression analysis model can be used to conduct the analysis of significance of influencing factor of land price. In the case of small sample or indefinite error distribution, there is a problem of unlikelihood of statistical referrer. So that, introduce Bootstrap method in the model to increase precision of estimated variance of parameters and reliability of statistical referrer of significance of influencing factor. Take an empirical analysis based on the data of land deal of Chongqing. The result indicates that it is very efficient to solve such problem by Bootstrap method.     

Analysis of Internal Force Calculation of Beams with Finite Length Bearing Several Point Loads and on Soil Foundation

For making the theoretic results close to the fact,two methods used to calculate the internal force of beams with finite length bearing several point loads and on soil foundation were compared.These two methods were based on the Winkler's assumption and the half-space elastic foundation theory respectively.Through theoretic analysis,the difference between the two methods was found.And with the aid of FLAC~(3D) analysis,it was clear that the results deduced by the method based on the Winkler's assumption were more close to the fact.     

考虑可动-不动水体假设的河套灌区适宜秋灌定额UBMOD模拟

针对土壤盐分物理非平衡运移定量描述的问题,为了探究内蒙古河套灌区根系层盐分累积与淋洗规律及适宜秋灌定额,该研究考虑可动-不动水体假设,构建UBMOD水盐运移模型,模拟分析了河套灌区永联试验区根系层土壤盐分累积与淋洗规律,探究不同水文年型、不同灌溉定额、不同灌溉水矿化度与不同秋灌定额条件下永联试验区根系层土壤盐分的淋洗规...